1. Field of the Invention
The present invention relates generally to a wiring harness arrangement for motorcycles.
2. Description of Relevant Art
Motorcycles are generally provided with a plurality of switches on and in the vicinity of the steering portion thereof so that operations such as actuation of lights, horns and/or turn signals may be easily performed while driving. These switches are connected to respective load circuits including horns, ignition coils, and lighting loads such as headlights, taillights and flashing lights. In addition, switches provided on the brake operating lever are also connected to respective load circuits such as stoplights. Each of such load circuits is provided with a subfuse for preventing an over-current and is supplied with a source voltage from a power source, i.e., a battery, through a combination switch and a main fuse.
According to the conventional practice, the subfuses in the load circuits of such a wiring harness for motorcycles are installed individually in respective branch lines between the main fuse and the load circuits, and are provided in the vicinity of the power source which is generally mounted on a longitudinally central portion of the vehicle body. On the other hand, the combination switch functioning as a main switch and the switches for the load circuits are located on and in the vicinity of the steering portion. Thus, it has been necessary to lead wiring from the power source to the combination switch located on or in the vicinity of the steering portion through the main fuse and return it in the vicinity of the power source to distribute to the subfuses before again leading the distributed wires to the vicinity of the steering portion to have them led via the operating switches to respective loads. Therefore, wires must be extended in both directions to and from the steering portion, thus resulting in excessively lengthy and complicated wiring.
In view of such difficulties and shortcomings, there has been proposed in U.S. Pat. No. 4,229,662 (issued Oct. 21, 1980) a wiring system such as shown in FIG. 6 of the accompanying drawings, in which a wiring harness 4 from a power source 3 mounted in the longitudinally central portion of a vehicle body 2 of a motorcycle 1 is led through a main fuse 5 to the vicinity of a steering portion of the motorcycle 1. More specifically, the wiring harness 4 is led to a combination switch 6 in the front portion of the vehicle body 2 and, after being distributed, to operation switches 8 of various load circuits on a handlebar 9 through respective subfuses 7, which are collectively installed on a top bridge, for example, and through branch lines 4a.
With the wiring system described above, however, connections of branch lines 4a must be provided within a main cable 4b when it is terminated with a coupler or the like. Because of the necessary inclusion of a plurality of branch lines 4a, the main cable 4b becomes bulky and the appearance thereof is adversely affected. Moreover, the durability tends to be reduced against the bending and tensile force due to the turning movements of the handlebar, and thus it is desired that the electrical reliability be improved.